Robert Leslie Watchmaker

Exciting discovery! An American Chronometer Maker & Inventor of the "Nautical Watch"

American Chronometer

Robert Leslie Nautical Watch

Robert Leslie Chronometer

Robert Leslie Movement

Early American Watchmakers

Robert Leslie was the first great American clock and watch inventor. Although best known as the principal in the Philadelphia firm Leslie & Price, he made clocks and watches for Thomas Jefferson and George Washington, and was in the forefront of clock and watch inventions in Philadelphia during the 1790's. 

Robert Leslie was awarded the first clock and the first watch patents in America, effective January, 1787, signed by George Washington, and received additional patents in both America and in England that further evidence his work on some of the greatest challenges in horology at the time including constant force and chronometer escapements, pendent winding for watches, and torsion pendulums for clocks. Leslie relocated to London in 1793 after a dispute with the Philadelphia clock and watch guild where he manufactured his inventions in partnership with Joseph Dodds, and supplied shops located in London, Philadelphia, and Baltimore. He returned to Philadelphia in 1800 and died in 1803.

Please note that horological publications prior to the ones cited here incorrectly state that Robert Leslie was from England or Scotland. In fact, he was born in Maryland. 

Leslie called one of his 1793 patented inventions the “Nautical Watch” which was intended to assist navigation at sea. This sophisticated timekeeper was the first two time-zone "captains" pocket watch made, and very likely the first watch movement designed by an American. 

A surviving example was discovered in rural southwest Virginia in 2012. Nautical Watch #5, shown above, is in its original wooden shipping box and was presumably manufactured as a salesman's sample to generate orders. It is configured with different hand styles and both front and rear winding to demonstrate the ways it could be ordered, and was also pre-tapped to allow easy installation of Leslie's patented pendent-wind invention. The movement has a going barrel (no fusee) and duplex escapement, although we know from recent research that it was also available with Leslie's chronometer escapement and temperature compensation.  “No 5 Leslie’s Patent” is printed on the dial. The movement signature plate is engraved “Brearley, Philadelphia.” James Brearley is a listed Philadelphia maker and Leslie associate who apparently retailed Robert Leslie’s clocks and watches.

A second Nautical Watch, signed by Leslie’s partner Joseph Dodds, was found by Dale Sardeson in the collection of the Russell-Cotes Art Gallery & Museum in Bournemouth, England. It is thankfully configured with Leslie’s patented escapement - - the chronometer escapement that Rupert Gould called a “free balance” escapement. The Russell-Cotes Nautical Watch was featured in an AHS Journal article in 2021 authored by Jonathan Betts and Dale Sardeson.

Additional References and recommended reading:

Article Robert Leslie Watchmaker
Article Robert Leslie Clock Maker